Primary/secondary piping loop interface apparatus

ABSTRACT

A primary-secondary loop piping system includes at least one boiler in fluid communication with a primary piping loop and at least one primary loop pump in the primary piping loop. At least one secondary piping loop branches away from the primary loop and returns downstream to the primary loop via a pair of closely spaced tees in a primary/secondary piping loop interface apparatus. The primary/secondary piping loop interface apparatus is of unitary construction and includes a secondary loop shut-off valve, drain valve and drain port in each branch of each secondary loop in which it is installed.

CROSS REFERENCE TO RELATED APPLICATIONS

This is a continuation-in-part (CIP) of U.S. patent application Ser. No.12/753,408 filed on Apr. 2, 2010 which is a continuation-in-part (CIP)of U.S. patent application Ser. No. 12/615,547 filed on Nov. 10, 2009which is a CIP of U.S. patent application Ser. No. 11/929,002 filed onOct. 30, 2007 which is a CIP of U.S. patent application Ser. No.11/648,376 filed on Dec. 29, 2006 which claims the benefit of U.S.Provisional Patent Application No. 60/756,007, filed on Jan. 4, 2006.The contents of U.S. patent application Ser. No. 12/753,408, U.S. patentapplication Ser. No. 12/615,547, U.S. patent application Ser. No.11/929,002, U.S. patent application Ser. No. 11/648,376 and U.S.Provisional Patent Application No. 60/756,007 are incorporated herein byreference in their entirety.

FIELD OF INVENTION

The present invention relates to valves and loop adapters, particularlyto a primary/secondary loop adapter and valve apparatus.

BACKGROUND OF INVENTION

Primary/secondary (“P/S”) piping systems are used to isolate thepressure differential established by a pump from those established byother pumps in the same system. P/S piping allows any pump in the systemto operate with virtually no tendency to induce flow, or even disturbflow, in other loops. P/S piping systems have become increasinglypopular in many commercial and residential plumbing systems, such ashydronic heating and cooling systems. In such systems purge valves areessential to the operation and maintenance of the systems. Hydronicheating systems have gained popularity due to the comfortable averagetemperature they provide and uniformity in heating. Hydronic systems usewater, or water-based solutions, to move thermal energy from where it isproduced to where it is needed. Thermal energy is absorbed by the waterat a heat source, conveyed by the water through the distribution piping,and finally released into a heated space by a heat emitter. Becausehydronic heating and cooling systems rely on the flow of water throughthe pipes, the presence of air bubbles or pockets within the piping canlead to inefficiency and malfunction of the system. Purge valves areused to empty the system of air upon installation and during maintenanceto provide for a more efficient system. Previous systems utilized purgevalves located on the secondary loop in order to remove air from thesecondary loop. The use of such valves can lead to pressuredifferentials that can affect the operation of the remainder of thesystem.

Hydronic systems utilize a liquid fluid to shift energy (i.e. BTUs) fromone location to another. Typically this is accomplished by heating up(or in cooling applications, cooling) a liquid, such as water, or amixture of water and other fluids (such as glycol antifreeze) to elevatethe boiling point and lower the freezing point, and pumping the liquidto another location where the captured energy in the fluid is released.The hydronic solution can be heated through the use of a boiler, solarenergy, geothermal pump, or any other means. The hydronic solution canbe cooled by use of a heat pump, geothermal pump, or other such means ofcooling the solution.

Hydronic systems require periodic maintenance, either to replace thewater in the system or to replace a mixture of water and antifreeze, toperform de-scaling of the heat exchangers or to flush out sludge, etc.This is accomplished by draining the hydronic system, flushing with ade-scaling and/or cleaning solution, draining and filling the systemback up with new fluid. Historically, purging a typical hydronic systemhas been accomplished by plumbing an assembly consisting of a boilerdrain connected to a check valve and connected to another boiler drain.This method, while functional, is far from ideal. There are severalconnections as part of the assembly which each provide a potential leakpath. Further, disadvantageously, the check valve typically does notprovide for complete shutoff and during normal operation of the systemthe check valve offers some internal flow restriction.

SUMMARY OF INVENTION

A P/S loop adapter and valve apparatus that allows for the eliminationof air from a piping system with no discernable pressure decrease isdisclosed. The adapter allows for power purging off a secondary loop inthe installation of hydronic systems. An embodiment of the presentinvention includes a valve body containing a flow channel extendingthrough the body from a first primary loop port to a second primary loopport. The valve body also contains first and second secondary loop portsin communication with the flow channel. A flow diversion device isdisposed in the valve body to control and alter the flow channel throughthe various ports of the valve body. The flow diversion device isdisposed within the flow channel between the first and second secondaryloop ports. The flow diversion device in a first position allows openflow through all ports of the valve. In a second position, the flowdiversion device directs flow from the first primary loop port to thefirst secondary loop port and flow from the second secondary loop portto the second primary loop port.

Embodiments of the present invention provide improvements overhistorical systems and methods for purging hydronic systems by combiningun-obstructive flow pattern of a ball valve and positive shutoffcharacteristics of a ball valve with fewer connection joints of thepurge and fill valve assembly to alleviates the detriments such asinternal flow restriction, incomplete shutoff and additional leak pathswhich are prevalent in the current systems and methods.

An illustrative embodiment of the present invention which is useful inpurging hydronic systems provides a purge and fill valve which utilizesthree ball valves that are combined into one valve assembly. The valvehas a main ball and two valves that communicate from the main valve toan external connection (i.e., drain and fill connections). When the mainball is closed, and the two valves for external communication areopened, the hydronic system can be conveniently and completely emptiedand filled from one location. New fluid can be introduced and push outthe old fluid, all at one time. The system does not need to be fullyemptied and then filled; a two stepped process, rather this is all donein one step.

It should be understood that labeling of “primary” flow path and“secondary” flow path is for illustration purposes and can be reversedwithout changing the scope of the present invention. For example, theprimary flow path could be called the secondary flow path and viceversa. In a typical hydronic system, the primary loop is usually, butnot always, associated with a boiler. The closely spaced teeshydraulically separates the primary flow path from the secondary flowpath. That is, flow in the primary flow path does not affect flow in thesecondary flow path and flow in the secondary flow path does not affectflow in the primary flow path.

In a further illustrative embodiment, where in comparison with theprevious embodiment, the “primary” loop is now designated as“secondary,” a valve body contains a first primary loop port, a secondprimary loop port, a first secondary loop port and a second secondaryloop port. The secondary loop ports are disposed at respective ends of alinear secondary loop portion of the valve body. A primary loop portionof the valve body is formed by a pair of closely spaced tees extendingfrom the secondary loop portion. At least one main valve portion isdisposed in at least one of the tees between the secondary loop portionand a primary loop port. A drain/venting valve portion extends from themain valve portion. A portion of the secondary loop portion between thetees is shared with the primary loop portion in which flow in a primaryloop and a secondary loop are hydraulically separated.

People having ordinary skill in the art should appreciate that closelyspaced tees are fluid flow path configurations in which two branchesfrom a single flow path in a T shaped arrangement are spaced apart fromeach other such that center lines of each of the branches are less thanabout four times the diameter of the single flow path from which theystem. People having ordinary skill in the art should also appreciatethat using closely spaced tees in a closed loop system creates ahydraulic separation where, due to lack of a pressure drop between thetees, a separate flow path is created or maintained through each of thetees.

Another illustrative embodiment of the invention provides aprimary/secondary loop purge valve in which a valve body contains afirst purge/fill port, a second purge/fill port, a first primary loopport and a second primary loop port. The primary loop ports are disposedat respective ends of a linear secondary loop portion of the valve body.A first purge/fill valve portion and a second purge/fill valve portionare formed in a pair of closely spaced tees extending from the primaryloop portion. A main valve portion is disposed in the primary loopportion in alignment with one of the closely spaced tees.

Yet another illustrative embodiment of the invention provides aprimary/secondary loop adapter having at least one main flow diversiondevice disposed in a respective at least one of a pair of closely spacedtees forming a primary loop portion of the adapter. A secondary loopportion of the adapter is formed by a linear adapter body from which thetees extend. The at least one flow diversion device may include a drainvalve portion extending therefrom. One or more primary loop ports of theprimary loop portion may include a flange adapted for connection to anapparatus, such as a pump, in the primary loop of a hydronic system.

Another embodiment of the invention provides a primary/secondary loopinterface apparatus including a unitary valve body having a primary loopportion for interfacing with a primary loop in a plumbing system and asecondary loop portion for interfacing with a secondary loop in theplumbing system. The secondary loop portion includes a first neckportion and a second neck portion extending from the primary loopportion and forming a pair of closely spaced tees suitable for hydraulicseparation of fluid between the primary loop and the secondary loop.Each of the first and second neck portions include a secondary loopshut-off valve and a drain port with corresponding drain valve. A flowpath between a secondary loop interface port in each neck portion isopen to the corresponding drain valve in both open and closedconfigurations of the corresponding secondary loop shut-off valve.

BRIEF DESCRIPTION OF THE DRAWINGS

The foregoing and other features and advantages of the present inventionwill be more fully understood from the following detailed description ofillustrative embodiments, taken in conjunction with the accompanyingdrawings in which:

FIG. 1 is an axial view of a first embodiment in accordance with thepresent invention;

FIG. 2 is a cut-away side view of the first embodiment in accordancewith the present invention;

FIG. 3 is a top-down cut-away view of the first embodiment in accordancewith the present invention;

FIG. 4 is a top-down cut-away view of a second embodiment having a flowdiversion device disposed within the first and second secondary loopports;

FIG. 5 is a top-down cut-away view of a third embodiment having multipleflow diversion devices disposed within the primary loop;

FIG. 6 is a plan view of a primary/secondary loop purge valve in normaloperating position according to a fourth illustrative embodiment of theinvention;

FIG. 7 is a section view of the primary/secondary loop purge valve innormal operating position according to the fourth illustrativeembodiment of the invention;

FIG. 8 is a plan view of the primary/secondary loop purge valve in apurging position according to the fourth illustrative embodiment of theinvention;

FIG. 9 is a section view of the primary/secondary loop purge valve inpurging position according to the fourth illustrative embodiment of theinvention;

FIG. 10 is a plan view of a primary/secondary loop purge valve in normaloperating position according to a fifth illustrative embodiment of theinvention;

FIG. 11 is a section view of the primary/secondary loop purge valve innormal operating position according to the fifth illustrative embodimentof the invention;

FIG. 12 is a plan view of the primary/secondary loop purge valve in apurging position according to the fifth illustrative embodiment of theinvention;

FIG. 13 is a section view of the primary/secondary loop purge valve inpurging position according to the fifth illustrative embodiment of theinvention.

FIG. 14 is a plan view of a primary/secondary loop adapter in normaloperating position according to a sixth illustrative embodiment of theinvention;

FIG. 15 is a section view of the primary/secondary loop adapter innormal operating position according to the sixth illustrative embodimentof the invention;

FIG. 16 is a plan view of the primary/secondary loop adapter in apurging position according to the sixth illustrative embodiment of theinvention;

FIG. 17 is a section view of the primary/secondary loop adapter in afirst purging position according to the sixth illustrative embodiment ofthe invention;

FIG. 18 is a section view of the primary/secondary loop adapter in asecond purging position according to the sixth illustrative embodimentof the invention;

FIG. 19 is a plan view of a primary/secondary loop adapter in normaloperating position according to a seventh illustrative embodiment of theinvention;

FIG. 20 is a plan view of an implementation of an eighth illustrativeembodiment of the primary/secondary loop adapter in which adrain/venting valve portion extends from each of the main valveportions;

DETAILED DESCRIPTION

Detailed embodiments of the present invention are disclosed herein,however, it is to be understood that the disclosed embodiments aremerely exemplary of the invention, which may be embodied in variousforms. Therefore, specific functional or structural details disclosedherein are not to be interpreted as limiting, but merely as a basis forthe claims and as a representative basis for teaching one skilled in theart to variously employ the present invention in virtually anyappropriately detailed embodiment.

Turning to FIG. 1, an axial view of an embodiment in accordance with thepresent invention is shown. A valve body 1 defines a flow channel 16that extends axially through the valve body 1 from a first primary loopport 18 to a second primary loop port. The valve body 1 also defines afirst secondary loop port 12 and a second secondary loop port (notshown). An end cap 2 is affixed to the valve body 1 at the first primaryloop port 18. An actuator 20 extends from the valve body 1 enabling afirst and second position of the valve. The actuator 20 includes ahandle 11 affixed to the valve body by a handle nut 10. A flow diversiondevice (not shown here) is connected to the handle 11. The position ofthe actuator 20 in a first position configures the flow diversion deviceto allow flow axially through the entire flow channel 16 from the firstprimary loop port to the second primary loop flow port as well asthrough the first and second secondary loop flow ports. In a secondposition of the actuator 20, the flow diversion device blocks the flowfrom the first primary loop port 18 to the second primary loop port. Inthis position, the first primary loop port 18 is in fluid communicationwith the first secondary loop port 12 only and the second primary loopport is in fluid communication with the second secondary loop port only.In a hydronic piping system, the valve in this position will break theprimary loop and force all flow into the secondary loop. This positionis used in such systems to purge the secondary loop of air duringinstallation or maintenance.

Turning now to FIG. 2 and FIG. 3, cut-away views of the first embodimentof the present invention are shown. FIG. 2 depicts the embodiment from aside-view, while FIG. 3 depicts the embodiment from a top-view. A valvebody 1 defines a flow channel 16 axially though the valve from the firstprimary loop port 18 to the second primary loop port 22. The firstsecondary loop port 12 and the second secondary loop port 14 are also influid communication with the flow channel 16. The end cap 2 is disposedinto the valve body 1 and mated with a seat retainer 3. The actuator 20extends from the valve body 1 containing a stem 6, a stem seal 7 and apacking gland 8. The actuator 20 also includes a handle 11 that isaffixed to the stem 6 with the handle nut 10. The actuator 20repositions the flow diversion device 5 to alter the flow channels ofthe valve. The flow diversion device 5 is disposed within the valve body1 in between the first secondary loop port 12 and the second secondaryloop port 14. The flow diversion device in this embodiment includes aball defining two openings equal in diameter to the diameter of the flowchannel 16. The flow diversion device 5 is disposed between valve seats4. The position of the actuator 20 in a first position positions theflow diversion device to allow flow axially through the entire flowchannel 16 from the first primary loop port to the second primary loopport as well as through the first and second secondary loop ports. In asecond position of the actuator 20, the flow diversion device blocks theflow from the first primary port 18 to the second primary port. In thisposition, the first primary loop port 18 is in fluid communication withthe first secondary loop port 12 only and the second primary loop portis in fluid communication with the second secondary loop port only.

An alternative embodiment of the present invention is described withreference to FIG. 4 which is similar to the embodiment shown in FIG. 3but also includes a flow diversion device disposed within each of thefirst and second secondary loop ports 12, 14. A valve body 1 defines aflow channel 16 axially though the valve from the first primary loopport 18 to the second primary loop port 22. The first secondary loopport 12 and the second secondary loop port 14 are also in fluidcommunication with the flow channel 16. A first secondary flow diversiondevice 30 is disposed within the first secondary loop port and isconfigurable to a first position which closes the first secondary loopport and to a second position which opens the first secondary loop port.A second secondary flow diversion device 32 is disposed within thesecond secondary loop port and is configurable to a first position whichcloses the second secondary loop port and to a second position whichopens the second secondary loop port.

In a still further alternative embodiment illustrated in FIG. 5 theprimary/secondary loop valve includes multiple valves in the primaryloop to effect flow in the primary and secondary loops. The multipleflow diversion devices, 30, 32 are disposed in the primary flow channel16 at the intersections of the primary and secondary flow paths. Theflow diversion devices are configured, as described hereinbefore, toalternately provide flow through at least one of the primary andsecondary loops.

The present invention also provides a method of purging a primary loopin a primary/secondary plumbing system using the inventive loop purgevalve by connecting the first secondary loop port to a flushing fluidsource and actuating the primary flow diversion device to configure theprimary flow diversion device in its second position to close the flowpath between the first primary loop port and second primary loop port.The first secondary flow diversion device is configured in the secondposition to allow the flushing fluid to flow into the first secondaryloop port and the second secondary flow diversion device is configuredin the second position to allow the flushing fluid to flow out from thesecond secondary loop port after flowing through the secondary loop(complete loop not shown). Upon completion of the purging procedure,each of the flow diversion devices can be configured to their respectivefirst positions.

Although one illustrative embodiment described herein includes diversiondevices in both of the secondary loop ports and in the primary looppath, one skilled in the art should appreciate that other configurationsof diversion devices can be implemented, such as a diversion device ineach of the first and second primary loop ports, or in othercombinations, such as a diversion device at inputs and/or outputs of theloop ports (primary and/or secondary).

FIG. 6 is a plan view of a primary/secondary loop purge valve in normaloperating position according to a fourth illustrative embodiment of theinvention. The embodiment includes a valve body 60 containing a firstprimary loop port 62, a second primary loop port 64, a first secondaryloop port 66 and a second secondary loop port 68. The secondary loopports 66, 68 are disposed at respective ends of a linear secondary loopportion 70 of the valve body 60. A primary loop portion 72 of the valvebody 60 is formed by a pair of “closely” spaced tees 74, 76 extendingfrom the secondary loop portion 70. At least one main valve portion 78is disposed in at least one of the tees 76 between the secondary loopportion 70 and a primary loop port 64. A drain/venting valve portion 80extends from the main valve portion 78. An end cap 81 is affixed to thevalve body 60 at a drain port 83 of the drain/venting valve portion 80.A portion of the secondary loop portion 70 between the tees 74, 76 isshared with the primary loop portion in which flow in a primary loop anda secondary loop are “hydraulically separated.”

A main actuator 85 extends from the valve body 60 enabling a first andsecond position of the main valve portion 78. A main flow diversiondevice (not shown here) is connected to a main handle 87 via the mainactuator 85. The main handle 87 is retained to the main actuator with anut 89. A purge valve handle 91 is connected to a purge valve flowdiversion device (not shown here) via a purge valve actuator (not shownhere). The purge valve handle 91 is retained to the purge valve actuatorby a screw 93.

FIG. 7 is a sectioned view of the primary/secondary loop purge valve innormal operating position according to the fourth illustrativeembodiment of the invention. A primary loop fluid flow path 82 is shownby arrows extending into tee 74, through the secondary loop portion 70and into tee 76. Fluid can flow in either direction along the primaryloop fluid flow path 82. A secondary loop flow path 84 is shown byarrows extending into the first secondary loop port 66 through thesecondary loop portion 70 and out from the second secondary loop port68. It should be understood that a common flow of both the primary loopflow path 82 and the secondary loop flow path 84 exists in the secondaryloop portion 70.

The main valve portion 78 is shown in the normal operation position inwhich fluid in the primary fluid flow path 82 can flow from secondaryloop portion 70 through the main valve portion 78 to the primary loopport 64. The main flow diversion device 79 in the main valve portion 78is shown in a first position to enable flow in the primary flow pathbetween tee 76 and the second primary loop port 64 while preventing flowto the drain/venting valve portion 80. In this illustrative embodiment,the main flow diversion device 79 is a first ball having a through hole95 extending through its center and a blind hole 97 extending orthogonalto the through hole to its center. The first ball is rotatable on anaxis of the main actuator 85 (FIG. 7) by movement of handle 87 (bestseen in FIG. 6) and main actuator 85 (FIG. 7). The first ball forms aseal with sealing portions 99 and 101.

The purge valve flow diversion device 103 in the drain/venting valveportion 80 is shown in its normally closed position in which fluid inthe primary flow path 82 is prevented from flowing between the mainvalve portion 78 and the drain port 83. In this illustrative embodiment,the purge valve flow diversion device 103 is a second ball having athrough hole extending through its center. The second ball is rotatableon an axis of the purge valve actuator (not shown) which extends throughits center and normal to the plane of drawing in FIG. 7 by movement ofpurge valve handle 91 (best seen in FIG. 6) and the purge valve actuatorretained thereto (not shown) by screw 93. The second ball forms a sealwith sealing portions 105 and 107.

FIG. 8 is a plan view of the primary/secondary loop purge valve in apurge/drain position according to the fourth illustrative embodiment ofthe invention. The main valve handle 87 and main actuator 85 are rotated90 degrees counter clockwise relative to their normal operatingposition. The purge valve handle 91 is rotated 90 degrees clockwiserelative to its normally closed position.

FIG. 9 is a section view of the primary/secondary loop purge valve in apurge/drain position according to the fourth illustrative embodiment ofthe invention. The primary loop fluid flow path 82 is shown by arrowsextending into tee 74, through the secondary loop portion 70 and intotee 76. Fluid in the primary flow path flows into main valve portion 78where it is diverted by the main flow diversion device 79 into thedrain/venting valve portion 80. Because the purge valve handle is in thepurge/drain position, fluid entering the drain/venting valve portion 80can flow through the purge valve flow diversion device 103 to the drainport 83. Protective cap 81 can be removed to vent or drain the systemvia the primary flow path 82.

Again, it should be understood that labeling of “primary” flow path and“secondary” flow path is for illustration purposes and can be reversedwithout changing the scope of the present invention. For example, theprimary flow path could be called the secondary flow path and viceversa. In a typical hydronic system, the primary loop is usually, butnot always, associated with a boiler. The closely spaced teeshydraulically separates the primary flow path from the secondary flowpath. That is, flow in the primary flow path does not affect flow in thesecondary flow path and flow in the secondary flow path does not affectflow in the primary flow path.

In normal operating position of valve body 60, the affect of closelyspaced tees 74, 76 and main valve portion 78 in the normal operatingposition is to hydraulically separate the primary flow path 82 from thesecondary flow path 84.

In a second configuration, the main valve portion 78 closes off theprimary flow path 82 and the drain/venting valve portion 80 is opened.The flow from the primary flow path 82 goes into a flow passageway,secondary loop portion 70, that is shared with the secondary flow path84, then back to the primary flow path 82. Because the main valveportion is “closed”, i.e. in its second configuration, and thedrain/venting valve portion 80 is open, for example any trapped air ispurged out of the system. Once the trapped air has been purged out ofthe system, the main valve portion 78 and the drain/venting valveportion 80 are returned to their normal operating positions.

Hydronic systems that use the primary/secondary piping method typicallyhave circulation pumps installed in each loop. The circulation pumpforces the fluid through the loop until the fluid encounters anobstacle, such as a shut valve. By providing a new path for the fluid toflow (e.g., out of the drain/venting valve portion 80) the fluid cancontinue to flow. Upon commissioning a piping system, or performingmaintenance on a system, air is tapped inside the piping system. Bypower pumping when the main valve portion 78 and drain venting valveportion 80 are in the drain/purge configuration, air is power purgedfrom the system via the drain port 83.

It should be appreciated that the flow directions in the primary flowpath 82 and the secondary flow path 84 can be reversed within the scopeof the present invention. In such cases, the main flow diversion device79 is oriented 180 degrees relative to the orientation shown so that theclosed portion is located downstream, i.e. toward the lower portion ofmain valve portion 79 when the primary flow path is oriented from thesecond primary loop port 64 toward tee 76.

FIG. 10 is a plan view of a primary/secondary loop purge valve in normaloperating position according to a fifth illustrative embodiment of theinvention. The embodiment includes a valve body 100 containing a firstpurge/fill port 102, a second purge/fill port 104, a first primary loopport 106 and a second primary loop port 108. The primary loop ports 106,108 are disposed at respective ends of a linear primary loop portion 110of the valve body 100. A first purge/fill valve portion 112 and a secondpurge/fill valve portion 114 are formed in a pair of closely spaced tees116, 118 extending from the primary loop portion 110. Persons havingordinary skill in the art should appreciate that the closely spaced tees116, 118 provide hydraulic separation in the primary loop portion 110between the first purge/fill valve portion 112 and the second purge/fillvalve portion 114. A main valve portion 120 is disposed in the primaryloop portion 110 in alignment with one of the closely spaced tees 116.

A main actuator 122 extends from the valve body 100 enabling a first andsecond position of the main valve portion 120. A main flow diversiondevice (not shown here) is connected to a main handle 124 via the mainactuator 122. The main handle 124 is retained to the main actuator witha nut 126. A first purge/fill valve handle 128 is connected to a firstpurge/fill valve flow diversion device (not shown here) via a firstpurge/fill valve actuator (not shown here). The first purge/fill valvehandle 128 is retained to the purge/fill valve actuator by a screw 130.A second purge/fill valve handle 132 is connected to a second purge/fillvalve flow diversion device (not shown here) via a second purge/fillvalve actuator (not shown here). The second purge/fill valve handle 132is retained to the second purge/fill valve actuator by a screw 134.

FIG. 11 is a section view of the primary/secondary loop purge valve innormal operating position according to the fifth illustrative embodimentof the invention. A primary loop fluid flow path 136 is shown by arrowsextending through the primary loop portion 110. In the configurationshown in FIG. 11, fluid can flow in either direction along the primaryloop fluid flow path 136.

The main valve portion 120 is shown in the normal operation position inwhich fluid in the primary fluid flow path 136 can flow between thefirst primary loop port 106 and the second primary loop port 108 via themain valve portion 120. The main flow diversion device 138 in the mainvalve portion 120 is shown in a first position to enable flow in theprimary flow path. The first purge/drain flow diversion device 140 andsecond purge/drain flow diversion device 142 are shown in a firstposition to prevent flow from the primary flow path to either the firstpurge/drain port 102 or the second purge/drain port 104. In thisillustrative embodiment, the main flow diversion device 138 is a firstball having a through hole 144 extending through its center and a blindhole 146 extending orthogonal to the through hole to its center. Thefirst ball is rotatable on an axis of the main actuator 122 (FIG. 10) bymovement of handle 124 and main actuator 122 (FIG. 10). The first ballforms a seal with sealing portions 148 and 150.

The first purge/fill valve flow diversion device 140 in the firstpurge/fill valve portion 112 is shown in its normally closed position inwhich fluid in the primary flow path 136 is prevented from flowingbetween the main valve portion 120 and the first purge/fill port 102. Inthis illustrative embodiment, the first purge/fill valve flow diversiondevice 140 is a second ball having a through hole extending through itscenter. The second ball is rotatable on an axis of the first purge/fillvalve actuator (not shown) which extends through its center and normalto the plane of drawing in FIG. 11 by movement of first purge/fill valvehandle 128 (FIG. 10) and the first purge valve actuator retained thereto(not shown) by screw 130 (FIG. 10). The second ball forms a seal withsealing portions 151 and 152.

The second purge/fill valve flow diversion device 142 in the secondpurge/fill valve portion 114 is shown in its normally closed position inwhich fluid in the primary flow path 136 is prevented from flowingbetween the primary loop portion 110 and the second purge/fill port 104.In this illustrative embodiment, the second purge/fill valve flowdiversion device 142 is a third ball having a through hole extendingthrough its center. The third ball is rotatable on an axis of the secondpurge/fill valve actuator (not shown) which extends through its centerand normal to the plane of drawing in FIG. 11 by movement of secondpurge/fill valve handle 132 (FIG. 10) and the first purge valve actuatorretained thereto (not shown) by screw 134 (FIG. 10). The second ballforms a seal with sealing portions 154 and 156.

FIG. 12 is a plan view of the primary/secondary loop purge valve in apurging position according to the fifth illustrative embodiment of theinvention. The main valve handle 124 and main actuator 122 are rotated90 degrees counter clockwise relative to their normal operatingposition. The first purge/fill valve handle 128 is rotated 90 degreesclockwise relative to its normally closed position and is obscured inthis view by the main valve handle 124. The second purge/fill valvehandle 132 is rotated 90 degrees counter-clockwise relative to itsnormally closed position.

FIG. 13 is a section view of the primary/secondary loop purge valve inpurging position according to the fifth illustrative embodiment of theinvention. A first purge/fill loop flow path 160 is shown by arrowsextending between primary loop port 106 and tee 116. Fluid in the firstpurge/fill loop flow path 160 can flow through main valve portion 120where it is diverted by the main flow diversion device 138 into thefirst purge/fill valve portion 112. Because the first purge/fill valvehandle 128 (best seen in FIG. 10) is in the purge/fill position, fluidentering the first purge/fill valve portion 112 can flow through thefirst purge/fill flow diversion device 140 to the first purge/fill port102.

A second purge/fill loop flow path 162 is shown by arrows extendingbetween primary loop port 108 and tee 118. Fluid in the secondpurge/fill loop flow path 162 can not flow through main valve portion120 because it is diverted by the main flow diversion device 138.Because the second purge/fill valve handle 132 (best seen in FIG. 12) isin the purge/fill position, fluid entering the second purge/fill valveportion 114 from primary loop port 108 can flow through the secondpurge/fill flow diversion device 142 to the second purge/fill port 104.

FIG. 14 is a plan view of a primary/secondary loop adapter in normaloperating position according to a sixth illustrative embodiment of theinvention. The embodiment includes a valve body 260 containing a firstprimary loop port 262, a second primary loop port 264, a first secondaryloop port 266 and a second secondary loop port 268. The secondary loopports 266, 268 are disposed at respective ends of a linear secondaryloop portion 270 of the valve body 260. A primary loop portion 272 ofthe valve body 260 is formed by a pair of “closely” spaced tees 274, 276extending from the secondary loop portion 270. A first main valveportion 278 is disposed in a first one of the tees 276 between thesecondary loop portion 270 and a primary loop port 264. A second mainvalve portion 300 is disposed in a second one of the tees 274 betweenthe secondary loop portion 270 and primary loop port 262. In thisillustrative embodiment, the primary loop port 262 includes a flange 302which may be adapted for connecting directly to an apparatus in theprimary loop, such as a pump, for example. The flange 302 may beimplemented as a multi-piece rotatable flange such as disclosed inco-pending, commonly owned U.S. patent application Ser. No. 12/749,020entitled, Rotatable Flange Apparatus and Method which is herebyincorporated by reference in its entirety.

A drain/venting valve portion 280 may extend from one or both main valveportions 278, 300. In the embodiment shown in FIG. 14 only one mainvalve portion 278 has a drain/venting valve portion 280 extendingtherefrom. Drain/venting valve portion 280 extends from the main valveportion 278. An end cap (not shown) may be affixed to the valve body 260at a drain port 283 of the drain/venting valve portion 280. It should beunderstood that a similar drain/venting valve portion with or without anend cap could also extend from main valve portion 300 within the scopeof the present disclosure.

A portion of the secondary loop portion 270 between the tees 274, 276 isshared with the primary loop portion in which flow in a primary loop anda secondary loop are “hydraulically separated.”

A main actuator 285 extends from the valve body 260 enabling a first andsecond position of the main valve portion 278. A main flow diversiondevice (not shown here) is connected to a main handle 287 via the mainactuator 285. The main handle 287 is retained to the main actuator witha nut 289. A purge valve handle 291 is connected to a purge valve flowdiversion device (not shown here) via a purge valve actuator (not shownhere). The purge valve handle 291 is retained to the purge valveactuator by a screw 293.

FIG. 15 is a sectioned view of the primary/secondary loop adapter innormal operating position according to a sixth illustrative embodimentof the invention. A primary loop fluid flow path 282 is shown by arrowsextending into tee 274, through the secondary loop portion 270 and intotee 276. Fluid can flow in either direction along the primary loop fluidflow path 282. A secondary loop flow path 284 is shown by arrowsextending into the first secondary loop port 266 through the secondaryloop portion 270 and out from the second secondary loop port 268. Itshould be understood that a common flow of both the primary loop flowpath 282 and the secondary loop flow path 284 exists in the secondaryloop portion 270.

The first main valve portion 278 is shown in the normal operationposition in which fluid in the primary fluid flow path 282 can flow fromsecondary loop portion 270 through the first main valve portion 278 tothe primary loop port 264. The second main valve portion 300 is alsoshown in the normal operation position in which fluid in the primaryfluid flow path 282 can flow from secondary loop portion 270 through thesecond main valve portion 300 to the primary loop port 262.

The main flow diversion devices 279, 279′ in the main valve portion 278,300 are shown in a first position to enable flow in the primary flowpath between tees 274, 276 and the primary loop ports 262, 264 whilepreventing flow to the drain/venting valve portion 280. In thisillustrative embodiment, the main flow diversion devices 279, 279′ areballs having a through hole 295, 295′ extending through their center. Inembodiments in which a drain/venting valve portion 280 is extended froma main valve portion as shown extending from the first main valveportion 278, the ball includes a blind hole 297, extending orthogonal tothe through hole to its center. The ball is rotatable on an axis of themain actuator 285, by movement of handles 287, 287′ and main actuators285, 285′ (best seen in FIG. 14). The ball forms a seal with sealingportions 299 and 301.

The purge valve flow diversion device 303 in the drain/venting valveportion 280 is shown in its normally closed position in which fluid inthe primary flow path 282 is prevented from flowing between the mainvalve portion 278 and the drain port 283. In this illustrativeembodiment, the purge valve flow diversion device 303 is a second ballhaving a through hole extending through its center. The second ball isrotatable, on an axis of the purge valve actuator (not shown) whichextends substantially through its center and normal to the plane ofdrawing in FIG. 15, by movement of purge valve handle 291 and the purgevalve actuator retained thereto by a screw 293 (best seen in FIG. 14).The second ball forms a seal with sealing portions 305 and 307.

FIG. 16 is a plan view of the primary/secondary loop adapter in apurge/drain position according to the sixth illustrative embodiment ofthe invention. The main valve handles 287, 287′ and main actuators 285(second main actuator not shown) are rotated 90 degrees counterclockwise relative to their normal operating position. The purge valvehandle 291 is rotated 90 degrees clockwise relative to its normallyclosed position. It should be appreciated that the actuators could beconfigured for rotation in the opposite directions.

FIG. 17 is a sectioned view of the primary/secondary loop adapter in afirst purge/drain position according to the sixth illustrativeembodiment of the invention. The primary loop fluid flow path 282 isshown by arrows extending into tee 274, through the secondary loopportion 270 and into tee 276. Fluid in the primary flow path flows intofirst main valve portion 278 where it is diverted by the first main flowdiversion device 279 into the drain/venting valve portion 280. Becausethe purge valve handle is in the first purge/drain position, fluidentering the drain/venting valve portion 280 from tee 276 can flowthrough the purge valve flow diversion device 303 to the drain port 283.A protective cap (not shown) can be removed to vent or drain the systemvia the primary flow path 282. Fluid in the primary flow path 282 thatis directed into the second main valve portion 300 is blocked by thesecond main flow diversion device 279′.

FIG. 18 is a sectioned view of the primary/secondary loop adapter in asecond purge/drain position according to the sixth illustrativeembodiment of the invention. The primary loop fluid flow path 282 isshown by arrows extending through the primary loop port 264 into thefirst main valve portion 278. Fluid in the primary flow path flows intofirst main valve portion 278 where it is diverted by the first main flowdiversion device 279 into the drain/venting valve portion 280. Becausethe purge valve handle is in the second purge/drain position, fluidentering the drain/venting valve portion 280 from primary loop port 264can flow through the purge valve flow diversion device 303 to the drainport 283. Fluid in the secondary flow path 284 that is directed into thesecond main valve portion 300 is blocked by the second main flowdiversion device 279′. Fluid in the secondary flow path 284 that isdirected into the first main valve portion 278 is blocked by the firstmain flow diversion device 279.

Persons having ordinary skill in the art should appreciate, withreference to FIGS. 15-18, that the second main flow diversion device279′ can be rotated to any one of three separate flow positions byrotation of the actuator 285 through about 180 degrees. That is, in theillustrative embodiment, the main flow diversion device operates as a3-way valve. In the various illustrative embodiments of the invention,either or both of the main flow diversion devices 279, 279′ can be soconfigured to operate as three way valves.

FIG. 19 is a plan view of a primary/secondary loop adapter 400 in normaloperating position according to a seventh illustrative embodiment of theinvention. The embodiment includes a valve body 360 containing a firstprimary loop port 362, a second primary loop port 364, a first secondaryloop port 366 and a second secondary loop port 268. The secondary loopports 366, 368 are disposed at respective ends of a linear secondaryloop portion 370 of the valve body 360. A primary loop portion 372 ofthe valve body 360 is formed by a pair of “closely” spaced tees 374, 376extending from the secondary loop portion 370. A main valve portion 402is disposed in a first one of the tees 374 between the secondary loopportion 370 and a primary loop port 362. In this illustrativeembodiment, the primary loop port 362 includes a flange 404 which may beadapted for connecting directly to an apparatus in the primary loop,such as a pump, for example.

FIG. 20 is a plan view of an eighth illustrative embodiment of theprimary/secondary loop interface apparatus. The primary-secondary pipingloop interface apparatus 500 includes a primary loop portion 502including a tubular fluid conduit having a circumferential sidewall, afirst end 504 and a second end 506 for interfacing with a primary loopin a plumbing system. A secondary loop portion 508 includes a first neckportion 510 and a second neck portion 512 extending from thecircumferential sidewall. The first neck portion 510 and second neckportion 512 are substantially parallel to each other and substantiallyperpendicular to the primary loop portion 502 to form a pair of closelyspaced tees suitable for hydraulic separation of fluid flow between theprimary loop portion 502 and the secondary loop portion 508.

The secondary loop portion 508 further includes at least one drain valveportion 514, 514′ extending from a corresponding neck portion 510, 512.The drain valve portion(s) 514, 514′ include a respective drain shut-offvalve 516, 516′ disposed therein and a respective drain port 518, 518′.The respective drain shut-off valve(s) 516, 516′ are arranged to enableor disable flow through the respective drain port(s) 518, 518′.

The secondary loop portion 508 also includes at least one secondary loopinterface port 520, 520′ terminating each respective neck portion 510,512 and at least one secondary loop shut-off valve 522, 522′ disposed inthe corresponding neck portion 510, 512 between the respective secondaryloop interface port 518, 518′ and the circumferential sidewall of theprimary loop portion 502.

In the eighth illustrative embodiment, the secondary loop shut-offvalves 522, 522′ includes an open operative position configured to opena main flow-path between the respective secondary loop interface port520, 520′ and the primary loop portion 502, and a closed operativeposition configured to close the main flow path between the respectivesecondary loop interface port 520, 520′ and the primary loop portion502. A drain flow path between the secondary loop interface port 520,520′ of the respective neck portion 510, 512 and the respective drainvalve portion 514, 514′ is configured to be open in both the openoperative position and the closed operative position of the secondaryloop shut-off valves 522, 522′.

In the illustrative embodiment, a rotatable flange 523 such as describedin commonly owned co-pending U.S. patent application Ser. No.12/749,020, which is incorporated herein by reference in its entirety,is configured to secure at least one of the secondary loop interfaceports 520, 520′ to an arbitrarily rotated flange interface in thesecondary loop of a primary/secondary loop plumbing system.

FIG. 21 shows a top cross sectional view of the eighth illustrativeembodiment wherein the section is taken through the secondary loopshut-off valves 522, 522′ and the drain shut-off valves 516, 516′ (FIG.20). The secondary loop shut-off valves 522, 522′ each include a flowdiversion device 524, 524′ disposed in a junction between a respectiveneck portion 510, 512 and corresponding drain valve portion 514, 514′.

Each of the flow diversion devices 524, 524′ include a main ball portion526, 526′ having a through hole 528, 528′ extending centrallythere-through and having a blind hole 530, 530′ extending orthogonallyto the through hole 528, 528′ from the center of the respective mainball portion 526, 526′. The main ball portion 526, 526′ is rotatableabout a main ball axis 532, 532′ through the center of the respectivemain ball portion 526, 526′ and orthogonal to a plane of the respectivethrough hole 528, 528′ and blind hole 530, 530′. In the open operativeposition of a respective secondary loop shut-off valve 522, 522′, therespective through hole 528, 528′ is aligned with the correspondingsecondary loop interface port 520, 520′ (FIG. 20) and wherein in theclosed operative position, the respective blind hole 530, 530′ isaligned with the corresponding secondary loop interface port 520, 520′(FIG. 20).

Each of the drain shut-off valves 516, 516′ includes a drain ballportion 534, 534′ having a through hole 536, 536′ extending centrallythere-through and is rotatable through an arc of about 90 degrees abouta drain ball axis 538, 538′. Each of the drain ball axes 538, 538′ areperpendicular to the through hole 536, 536′ of the drain ball portionand parallel to the corresponding main ball axis 532, 532′.

In the illustrative embodiment, a first drain valve portion 514 isparallel to the primary loop portion 502 and directed away from thesecond neck portion 512, and the second drain valve portion 514′ isdirected generally toward the first neck portion 510 and oriented at anangle 540 of about 45 degrees relative to the primary loop portion 502in this illustrative embodiment. An angle of 0 to 90 degrees orpreferably 15-75 degrees may be implemented to provide clearance aroundthe first neck portion 510 for access to the drain valve port 518′ ofthe second drain valve portion 514′.

An implementation of the primary/secondary loop interface apparatusaccording to the eighth embodiment of the invention in aprimary/secondary loop piping system is described with reference to FIG.22. The primary-secondary loop piping system includes at least oneboiler 602 in fluid communication with a primary piping loop 604. Atleast one primary loop pump 606 is installed in the primary piping loop604. At least one secondary piping loop 608, 608′, 608″ branches awayfrom the primary loop 604 and returns downstream to the primary loop 608via a pair of closely spaced tees in a primary-secondary piping loopinterface apparatus 500.

In the primary/secondary loop piping system shown in FIG. 22, each ofthe primary-secondary piping loop interfaces 500 are substantiallyidentical to those described hereinbefore with reference to FIGS. 20 and21.

At least one secondary loop pump 610 is installed in each of thesecondary piping loops 608. In each secondary loop 608, the secondaryloop pump 610 is mounted to a flange 523 on one of the secondary loopinterface ports (520′ FIG. 20). In the illustrative embodiment theflange 523 is a rotatable flange as described in the referenced U.S.patent application Ser. No. 12/749,020. However, it should be understoodthat various alternative embodiments could be configured wherein flange523 is a fixed flange within the scope of the present disclosure. Therotatable flange 523 is configurable to secure a secondary loopinterface port (520′ FIG. 20) to an arbitrarily rotated flange interfacein the secondary loop 608, such as a mating flange on the secondary looppump 610. The rotatable flange allows the secondary loop pump 610 orother component having a flange interface to be connected to theprimary/secondary loop interface apparatus 500 over a range of relativeangular displacements between the secondary loop pump 610 and theprimary/secondary loop interface apparatus 500. This is beneficial wheremounting a pump in a particular fixed angular displacement could bedifficult or impossible due to space constraints, for example.

In the illustrative embodiment, the primary/secondary piping loop systemincludes a plurality of secondary piping loops 608 wherein one or moreof the secondary piping loops 608 each constitute a separate heatingzone, for example. Another of secondary piping loops 608 couldconstitute a snow melt system, for example, or other zone loop.

In the illustrative embodiment the boiler 602 is also installed in asecondary loop referred to herein as a near boiler piping loop 612. Asecondary loop pump 614 in the near boiler piping loop 612 can beinstalled to the primary-secondary piping loop interfaces 500 in thesame manner as described with regard to the secondary loop pumps 610 insecondary loops 608. Alternative embodiments of a near boiler pipingloop 612 may include a secondary loop pump which is incorporatedinternally within the boiler rather than external to the boiler 602 asshown in FIG. 22. In these alternative embodiments, the flange 523 onthe primary-secondary piping loop interfaces 500 may be replaced by aunion fitting for connecting to piping in the near boiler piping loop612.

Illustratively, the primary loop pump 606 is installed in the primaryloop 604 between the near boiler piping loop 612 and the other secondaryloops 608 wherein energy from the boiler is distributed. It should beunderstood that alternative embodiments within the scope of the presentdisclosure could include a boiler installed in the primary loop, ratherthan in a secondary loop as shown in FIG. 22. Such embodiments mayinclude a pump incorporated internally with the boiler rather than aseparately installed primary loop 606 as shown in FIG. 22.

In another implementation, the primary-secondary piping loop interfaceapparatus 500 according to the eighth embodiment of the invention isincluded in a near boiler piping adapter system which is described withreference to FIG. 23. The near boiler piping adapter system 700,includes a primary-secondary loop interface apparatus 500 which wasdescribed hereinbefore with reference to FIGS. 20 and 21 and a returnbranch pipe section 702 attached to the second secondary loop interfaceport (520 FIG. 20) of the primary-secondary loop interface apparatus500.

In the illustrative embodiment, a first flange 523 is configured on thefirst secondary loop interface port (520′ FIG. 20) to allow attachmentof a first flange interface of a circulation pump 704 to the firstsecondary loop interface port (520′ FIG. 20). In the illustrativeembodiment the first flange 523 is a rotatable flange configured on thefirst secondary loop interface port (520′ FIG. 20) to allow attachmentof an arbitrarily rotated first flange interface of the circulation pump704 to the first secondary loop interface port (520′ FIG. 20).

The return branch pipe section 702 includes a return branch boilerattachment tee 706. The return branch boiler attachment tee 706 includesa return branch boiler attachment fitting 708 and a return branchauxiliary attachment point 710.

A second flange 712 is configured on wye strainer 714 which is attachedto a supply branch pipe section 716 for mounting the wye strainer 714 toa second flange interface of the circulation pump 704. In theillustrative embodiment, the second flange 712 is a rotatable flangeconfigured on the wye strainer 714 to allow attachment of an arbitrarilyrotated second flange interface of the circulation pump 704. A wyestrainer 714 with a rotatable flange which is suitable for use in thenear boiler piping adapter system 700 is described in Applicant'sco-pending U.S. patent application entitled ROTATABLE FLANGE WYESTRAINER, attorney docket no. 55807.16-CIP, which is aContinuation-in-Part of U.S. patent application Ser. No. 12/749,020,filed on Mar. 29, 2010 which are incorporated herein by reference intheir entirety.

The supply branch pipe section 716 includes a supply branch boilerattachment tee 718. In the illustrative embodiment, the supply branchboiler attachment tee 718 includes a supply branch boiler attachmentfitting 720 and a supply branch auxiliary attachment point 722. Thesupply branch auxiliary attachment point 722 and return branch auxiliaryattachment point 710 can be used for attaching an indirect water heaterto the boiler, for example.

A union fitting 724 connects the return branch pipe section 702 to thesecond secondary loop interface port (520, FIG. 20). In the illustrativeembodiment, the union fitting 724 includes a gauge hole configured forconnecting a gauge 726 such as a pressure gauge or temperature gauge,for example, to the union fitting 724.

In the illustrative embodiment, the return branch pipe section includesa knee portion 728 configured to offset the return branch boilerattachment tee 706 from the supply branch boiler attachment tee 718.

Illustrative embodiments of the present invention also provide a methodof servicing a secondary loop in a primary-secondary loop piping systemby operating the primary-secondary piping loop interface apparatusdescribed hereinbefore with reference to FIGS. 20 and 21. In anembodiment described with reference to FIG. 24, the method 800 ofoperating the primary-secondary piping loop interface apparatus includesthe step of setting each of the at least one secondary loop shut-offvalves (522, 522′, FIG. 20) to their respective closed operativeposition 802 so that there can be no flow through those valves.

In the illustrative embodiment, a draining operation of theprimary-secondary loop interface apparatus requires the step of draininga corresponding secondary loop of the primary-secondary loop pipingsystem by opening the respective drain shut-off valve of at least one ofthe drain valve portions so there can be flow through at least one ofthe drain ports 518, 518′.

In the illustrative embodiment, a filling operation of theprimary-secondary loop piping interface includes the steps of filling acorresponding secondary loop of the primary-secondary loop piping systemby connecting a fill hose to at least one of the drain ports 518, 518′of at least one of the drain valve portions and opening the respectivedrain shut-off valve of the drain valve portion 808.

In the illustrative embodiment, a flushing operation of theprimary-secondary loop piping interface includes the steps of flushing acorresponding secondary loop of the primary-secondary loop piping systemby connecting a fill hose to at least one of the drain ports of at leastone of the drain valve portions 810, opening the respective drainshut-off valve of the respective drain valve portion 812 and opening thedrain shut-off valve in another of the at least one drain valve portions814.

It should be appreciated that a “diversion device” can be one or moredevices for diverting flow in a desired manner. The descriptions of flowpaths and flow directions herein which identify flow paths or otherelements with labels such as primary and secondary, or first and secondare for illustrative purposes to provide labels for a particularembodiment, drawing or claim and are not indicative of a hierarchalrelationship between the elements. Further it should be understood thatsuch labels may be reversed in any of the embodiments described orclaimed herein without affecting the scope of the present disclosure.Similarly, it should be understood that the clockwise orcounterclockwise direction of rotations of certain elements such as flowdiversion devices and handles described herein are for illustrativepurposes only and may generally be reversed without changing the scopeof the present disclosure.

While the invention has been described with reference to illustrativeembodiments, it will be understood by those skilled in the art thatvarious other changes, omissions and/or additions may be made andsubstantial equivalents may be substituted for elements thereof withoutdeparting from the spirit and scope of the invention. In addition, manymodifications may be made to adapt a particular situation or material tothe teachings of the invention without departing from the scope thereof.Therefore, it is intended that the invention not be limited to theparticular embodiment disclosed for carrying out this invention, butthat the invention will include all embodiments falling within the scopeof the appended claims. Moreover, unless specifically stated any use ofthe terms first, second, etc. do not denote any order or importance, butrather the terms first, second, etc. are used to distinguish one elementfrom another.

1. A primary-secondary loop piping system for at least one boiler influid communication with a primary piping loop comprising: at least oneprimary loop pump in the primary piping loop; at least one secondarypiping loop branching away from the primary loop and returningdownstream to the primary loop; and a primary-secondary piping loopinterface apparatus comprising a pair of closely spaced tees configuredto effect fluid communication in the primary piping loop and the atleast one secondary piping loop.
 2. The system of claim 1, comprising:at least one secondary loop pump in the at least one secondary pipingloop.
 3. The system of claim 1, wherein the primary-secondary pipingloop interface comprises: a primary loop portion including a tubularfluid conduit having a circumferential sidewall, a first end and asecond end connected to the a primary loop in a plumbing system; asecondary loop portion including a first neck portion extending from thecircumferential sidewall and a second neck portion extending from thecircumferential sidewall, wherein the first neck portion and second neckportion are substantially parallel to each other and substantiallyperpendicular to the primary loop portion to form a pair of closelyspaced tees suitable for hydraulic separation of fluid flow between theprimary loop portion and the secondary loop portion; the secondary loopportion further including at least one drain valve portion extendingfrom a corresponding at least one of the first neck portion and/or thesecond neck portion, wherein the drain valve portion(s) include arespective drain shut-off valve disposed therein and a respective drainport, the respective drain shut-off valve(s) arranged to enable ordisable flow through the respective drain port(s); and the secondaryloop portion further including at least one secondary loop interfaceport terminating each respective neck portion and at least one secondaryloop shut-off valve disposed in a corresponding at least one of thefirst neck portion and/or second neck portion between the respectivesecondary loop interface port and the circumferential sidewall, whereinthe secondary loop interface ports are connected to the secondary pipingloop.
 4. The system of claim 3, wherein the at least one secondary loopshut-off valve includes an open operative position configured to open amain flow-path between the respective secondary loop interface port andthe primary loop portion, and a closed operative position configured toclose the main flow path between the respective secondary loop interfaceport and the primary loop portion, wherein a drain flow path between thesecondary loop interface port of the respective neck portion and therespective drain valve portion is configured to be open in both the openoperative position and the closed operative position of the secondaryloop shut-off valve.
 5. The system of claim 3, wherein the secondaryloop pump is mounted to a flange on one of the secondary loop interfaceports.
 6. The system of claim 3, comprising: a rotatable flangeconfigured to secure at least one of the secondary loop interface portsto an arbitrarily rotated flange interface in the secondary loop,wherein said secondary loop pump is mounted to the rotatable flange. 7.The system of claim 1, wherein the at least one secondary piping loopcomprises a heating zone.
 8. The system of claim 1, wherein the at leastone secondary piping loop comprises a snow melt system.
 9. The system ofclaim 1, wherein the at least one boiler is disposed in one of the atleast one secondary piping loops.
 10. The system of claim 1, wherein theat least one secondary piping loops includes a plurality secondarypiping loops comprising separate heating zones.
 11. A method ofservicing a secondary loop in a primary-secondary loop piping system,comprising: operating a primary-secondary piping loop interfaceapparatus, wherein the primary-secondary piping loop interface apparatusincludes: a primary loop portion including a tubular fluid conduithaving a circumferential sidewall, a first end and a second endconnected to the a primary loop in a plumbing system; a secondary loopportion including a first neck portion extending from thecircumferential sidewall and a second neck portion extending from thecircumferential sidewall, wherein the first neck portion and second neckportion are substantially parallel to each other and substantiallyperpendicular to the primary loop portion to form a pair of closelyspaced tees suitable for hydraulic separation of fluid flow between theprimary loop portion and the secondary loop portion; the secondary loopportion further including at least one drain valve portion extendingfrom a corresponding at least one of the first neck portion and/or thesecond neck portion, wherein the drain valve portion(s) include arespective drain shut-off valve disposed therein and a respective drainport, the respective drain shut-off valve(s) arranged to enable ordisable flow through the respective drain port(s); the secondary loopportion further including at least one secondary loop interface portterminating each respective neck portion and at least one secondary loopshut-off valve disposed in a corresponding at least one of the firstneck portion and/or second neck portion between the respective secondaryloop interface port and the circumferential sidewall, wherein thesecondary loop interface ports are connected to the secondary pipingloop; configuring the at least one secondary loop shut-off valve to anopen operative position to open a main flow-path between the respectivesecondary loop interface port and the primary loop portion, and to aclosed operative position to close the main flow path between therespective secondary loop interface port and the primary loop portion;and configuring a drain flow path between the secondary loop interfaceport of the respective neck portion and the respective drain valveportion to be open in both the open operative position and the closedoperative position of the secondary loop shut-off valve.
 12. The methodof claim 11, further including the step of: setting each of the at leastone secondary loop shut-off valves to their respective closed operativeposition.
 13. The method of claim 11, wherein operating theprimary-secondary piping loop interface further includes the step of:draining a corresponding secondary loop of the primary-secondary looppiping system by opening the respective drain shut-off valves at leastone of the drain valve portions.
 14. The method of claim 11, whereinoperating the primary-secondary loop piping interface further includesthe step of: filling a corresponding secondary loop of theprimary-secondary loop piping system by connecting a fill hose to atleast one of the drain ports of at least one of the drain valve portionsand opening the respective drain shut-off valve of the drain valveportion.
 15. The method of claim 11, wherein operating theprimary-secondary loop piping interface includes the step of: flushing acorresponding secondary loop of the primary-secondary loop piping systemby connecting a fill hose to at least one of the drain ports of at leastone of the drain valve portions and opening the respective drainshut-off valve of the respective drain valve portion; and opening thedrain shut-off valve in another of the at least one drain valveportions.